Sound reproducer



Jun 1, 1929- R. E. B. WAKEFIELD 1,71 09 SOUND REPRODUCER Original Filed April 5, 1923 nnhwakefield WITNESSES: lNVENTOR Wei/6 I BY ATTORNEY Patented June 11, 1929.

UNITED siu ifras RICHARD E. B. WAKEFIELD, OF CHESTER, PENNSYLVANIA.

SOUND REPRODUCER.

' Application filed April 5, 1923, Serial No. 630,127. Renewed November 1, 1928.

My invention relates to a sound producing device and it has for its object to provide apparatus of the character designated which may readily be employed in connection with the reproducer and horn of a phonograph in order to permit the use thereof as a telephonic loud speaker.

More specifically, my invention relates to a receiver adapted to be mounted on a phonograph table and provided with a vibration transmitting member projected outwardly and upwardly so as to be adapted to be received within the needle clamp of the phonograph reproducer, said transmitting member preferably being under initial strain for a purpose to be hereinafter pointed out, and said receiver setting up vibrations in accordance with the-sound to be produced and said vibrations being transmitted to the reproducer diaphragm where the sound is developed for emission through the phonograph horn.

In the accompanying drawing, Fig. 1 is a side view, partially in section and partially in elevation, of a phonograph reproducer together with one form of receiver, constructed in accordance with my invention, and Fig. 2 is a view similar to Fig. 1' and illustrating a modified form of receiver.

In the reception of telephonic communication, either by wire or by wireless, it is frequently desirable that the sound be amplified and thrown out into a large room for the entertainment of a large number of people, and it has been proposed to perform this function by the use of special loud speaking devices. I have found that the horn and reproducer of the ordinary phonograph are well adapted for the development of the necessary loud sounds, provided the necessary vibration be imparted to the reproducer diaphragm. In accordance with my invention, therefore, I provide a relatively powerful telephonic receiving device and I then mechanically connect the vibratory member thereof with the reproducer lever by means of a suitable link clamped within the needle clamp of the reproducer lever. Said link is preferably placed under initial torsional strain in order that it may transmit vibrations with a minimum of lost motion. By this means, the receiving device is accurately positioned and, furthermore, the vibration transmitting connection is free from lost motion tending to and contains a receiver embodying a coil 11 7 and a magnetic diaphragm 12. A vibration,

transmitting member 13 is attached to the center of, the diaphragm 12, as by soldering or riveting, and projects outwardly through the wall of the casing 10 and is thence bent upwardly so as tobe readily introduced Within the needle clamp 9 by the application of a slight lateral pressure to the tip thereof, imparting an initial twist to the portion thereof which is normal to the diaphragm and lateral flexure to the remainder thereof.

Suitable binding posts 14 and 15 are provided and may be connected either to a telephone circuit or to the output circuit of a wireless'outfit for the suitable energization of the coil 11.

Having thus described the arrangement of apparatus embodying my invention, the operation and use thereof is as follows The casing 10 is placed in a suitable position on the table 5 and the usual needle having been removed from the needle clamp 9, the member 13 is placed therein and securely attached, whereupon the vibration of the diaphragm 12 by the magnetic effect of the 0011 11 is transmited through the member 13 and the lever 8, actuating the reproducer diaphragm 7 and causing the development of loud clear sounds from the phonograph horn.

Referring to the form of my invention shown in Fig. 2, which may be more powerful in action than the form of my device shown in Fig. 1, I provide a base member 20 for placing upon the phonograph table and an upwardly extending standard thereupon 1s clamped upon the reproducer box as shown at 22. A suitable coil 23 is provided with a substantially closed magnetic circuit embodying a central member 24, a surrounding shell 25 and a vibratory armature 26. The armature 26 isprevented fromlooseness or rattling by a spring member 27' which may also serve to assist'in closing the magnetic circuit.

' 20 upon the reproduced box 6,

A vibration transmitting member 28 is suit- I ably mounted on the upper end of the armawill be apparent from the foregoing description. The energization of the coil 23 causes vibration of the armature 26 in accordance with the sound to be reproduced and this vibration is transmitted via the member 28 and the lever 8 to the reproducer 65. Exceptionally powerful vibrations may be developed by 'the substantially closed magnetic structure shown and the clamping of the base member together with mounting at 29, permits the the adjustable the entire apparatus for most adjustment of effective operation.

While I preferably so form the transmitting links 13 and 28 that the inclination of the free end thereof, when unrestrained, is either greater or less than the inclination imposed by clamping within the needle socket, necessitating slight fiexure of the member in order to introduce the same into the socket, this construction is not essential to the operativeness I of my device but is adopted in order to'more are imposed by completely eliminate rattling and lost motion. If desired, the inclination of the free end of the link may coincide with that imposed by the needle socket so that attachment may be made without flexure of the members 13 or 28.

While I have shown my invention in but two forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. In a sound-producing device, the combination with a phonograph reproducer embodying a needle-holder, of a telephone receiver embodying a vibratory diaphragm, and a member attached to said diaphragm and adapted to be clamped within said needleholder, whereby vibrations of said diaphragm are transmitted to said reproducer, causing the emission of sound therefrom.

2. In a sound-producing device, the combination with a base member adapted to rest upon the table of a phonograph, of a vibratory magnetic diaphragm carried thereby, an actuating coil in operative proximity to said diaphragm, and a sound-transmittin link fastened substantially at the center 0? said and then upwardly,

diaphragm and extending normally thereto and then upwardly, the u wardly extending end thereof being adapte to be received in the needle clamp of said phonograph.

3. In a sound-producing device, the combination with a base member adapted to rest upon a phonograph table, of a vibratory member mounted thereupon, actuating means therefor, and an outwardly and upwardly extending member operatively attached to said vibratory member and adapted to have its upwardly extending end received within the needle-clamp of the phonograph reproducer, the normal inclination of the upwardly extending portion of said member differing slightly from the inclination imposed thereupon by the needle-clamp, whereby a slight torsional strain is imposed upon the outwardly extending portion of said member and a slight lateral flexure is applied to the upwardly extending portion thereof when confined in the needle-clamp. 4:. In a sound-producing device, the combination with a base member adapted to rest upon the table of a phonograph, of a vibratory magnetic diaphragm carried thereby, an actuating coil in operative proximity to said diaphragm, and a sound-transmitting link fastened substantially at the center of said diaphragm and extending normally thereto the upwardly extending end thereof being adapted to be received in the needle clamp of said phonograph, the nor; mal inclination of the upwardly extending portion of said link differing slightly from the inclination imposed thereupon by the needle clamp, whereby a slight torsional strain is imposed upon the outwardly extending portion of said link and a slight lateral flexure is applied to the upwardly extending portion thereof when confined in the needle clamp.

5. In a mechanism for adapting a phonograph as a telephone loud-speaker, the combination with means for developing a vibration in accordance. with the sound to be transmitted, of means for transmitting said vibrations to the phonograph reproducer embodying a member rigidly attached to said vibration developing means and adapted to be received and clamped within the needle socket of said phonograph in the absence of the needle, said member being at all times under strain when clamped in the needle socket.

6. An arrangement for mechanically associating a telephone receiver with a sound reproducing apparatus having the usual diaphragm and socket for replacing reproducing needles, said arrangement comprising a diaphragm for the telephone receiver, said diaphragm having mounted thereon a needle arm, and means to secure the needle arm in ,said socket.

7. An arrangement for separably associatmg a telephone receiver with a sound repromember and a rigid connecting link rigidly secured to said vibratory member andalso secured to said actuating means, whereby movements of said vibratory member are directly receiver, a needle transmitted to said actuating means without 10st motion or friction losses.

' 9. In a sound reproducing device, the combination with the sound reproducing device comprisin a diaphragm and means for mechanica ly actuating the same, of an electro-responsive device having a vibratory member, and a connectin link between said vibratory member and said actuatin means rigidly secured to said vibratory-member, said connecting link being subjected to'a torsional strain when secured to said mechanical means.

In testimony whereof, I have hereunto subscribed my name this 19th day of March,

1923. RICHARD E. BJEVAKEFIELD. 

